Pregnancy Due Date Calculator
Estimate your due date based on LMP, conception date, or IVF transfer. See your pregnancy timeline week by week.
Your Results
How It Works
Three methods to estimate your due date, all backed by standard medical practice.
LMP Method
The standard method: add 280 days (40 weeks) from the first day of your last menstrual period. Adjusts for cycle length if different from 28 days.
Conception Method
If you know your conception date, we add 266 days (38 weeks). This method is more accurate if you tracked ovulation or used fertility monitoring.
IVF Method
For IVF pregnancies: add 263 days for day-3 transfers or 261 days for day-5 transfers. This is the most precise method when transfer date is known.
Frequently Asked Questions
Common questions about due dates and pregnancy calculation.
The most common method uses your Last Menstrual Period (LMP) date plus 280 days (40 weeks). If you know your conception date, add 266 days (38 weeks). For IVF, add 263 days for a 3-day transfer or 261 days for a 5-day transfer.
Only about 5% of babies are born exactly on their due date. Most are born within two weeks before or after. The due date is an estimate, and full-term is considered 37-42 weeks. Your healthcare provider may adjust the date based on ultrasound measurements.
LMP (Last Menstrual Period) is the first day of your last period. Conception typically occurs about 14 days after LMP (during ovulation). Due dates calculated from LMP add 280 days, while conception-based dates add 266 days — the difference accounts for the two weeks before ovulation.
If your cycle length differs from the standard 28 days, adjust the cycle length setting in the calculator. For longer cycles, ovulation occurs later, which shifts the due date forward. For shorter cycles, ovulation occurs earlier, shifting the due date backward.
The zodiac sign is calculated based on the due date and is provided for fun. Each zodiac sign corresponds to a date range and is associated with certain personality traits. Remember that fewer than 1 in 20 babies arrive exactly on their calculated due date.